NM_000747.3:c.1482G>T

Variant names:

• chr17-7456699-G-T
• rs747251351
• NM_000747.3:c.1482G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000747.3(CHRNB1):​c.1482G>T​(p.Leu494Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,132 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L494S) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 31)
• Consequence: CHRNB1 NM_000747.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.95
• Publications: 0 publications found

Genes affected

CHRNB1 (HGNC:1961): (cholinergic receptor nicotinic beta 1 subunit) The muscle acetylcholine receptor is composed of five subunits: two alpha subunits and one beta, one gamma, and one delta subunit. This gene encodes the beta subunit of the acetylcholine receptor. The acetylcholine receptor changes conformation upon acetylcholine binding leading to the opening of an ion-conducting channel across the plasma membrane. Mutations in this gene are associated with slow-channel congenital myasthenic syndrome. [provided by RefSeq, Jul 2008]

CHRNB1 Gene-Disease associations (from GenCC):

• congenital myasthenic syndrome 2C

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp
• congenital myasthenic syndrome 1A

  Inheritance: AD Classification: STRONG Submitted by: PanelApp Australia
• congenital myasthenic syndrome 2A

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.15580642).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000747.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRNB1	NM_000747.3	MANE Select	c.1482G>T	p.Leu494Phe	missense	Exon 11 of 11	NP_000738.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CHRNB1	ENST00000306071.7	TSL:1 MANE Select	c.1482G>T	p.Leu494Phe	missense	Exon 11 of 11	ENSP00000304290.2
	CHRNB1	ENST00000536404.6	TSL:2	c.1266G>T	p.Leu422Phe	missense	Exon 10 of 10	ENSP00000439209.2
	CHRNB1	ENST00000576360.1	TSL:3	c.1119G>T	p.Leu373Phe	missense	Exon 10 of 10	ENSP00000459092.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152132 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251466 AF XY: 0.00

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152132 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74302

African (AFR) AF: 0.0000483 AC: 2 AN: 41416

American (AMR) AF: 0.00 AC: 0 AN: 15274

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68024

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Congenital myasthenic syndrome 2A (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.18	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	19
DANN	Uncertain	1.0
DEOGEN2	Benign	0.068	T
Eigen	Benign	-0.070
Eigen_PC	Benign	0.053
FATHMM_MKL	Uncertain	0.82	D
M_CAP	Benign	0.033	D
MetaRNN	Benign	0.16	T
MetaSVM	Benign	-0.83	T
MutationAssessor	Benign	0.41	N
PhyloP100		1.9
PrimateAI	Benign	0.38	T
PROVEAN	Benign	-1.0	N
REVEL	Benign	0.19
Sift	Benign	0.68	T
Sift4G	Benign	0.69	T
Polyphen		0.96	D
Vest4		0.26
MutPred		0.32		Loss of disorder (P = 0.2174)
MVP		0.89
MPC		0.63
ClinPred		0.44	T
GERP RS		3.6
Varity_R		0.089
gMVP		0.52

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs747251351; hg19: chr17-7360018;